The aim of this study is to (1) examine changes in amount and isomeric composition of retinyl esters (particularly the 11-cis isomer) in the retinal pigment epithelium; (2) the appearance and amount of interstitial retinol-binding protein (IRBP) during normal development and maturation of the neural retina and (3) to interrelate these with retinal structure and rhodopsin content. Eyes will be enucleated from dark adapted C57BL/6J++/++ mice at various stages of development (newborn 4 months). These eyes will be homogenized and aliquots taken for high pressure liquid chromatography analysis of retinyl ester content and rhodopsin content determined. IRBP content will be determined by rocket immunoelectrophoresis, its appearance and location determined by immunohistochemistry (antibody provided by C.D.B. Bridges). Results from this study will provide further information on the origins and utilization of 11-cis and all-trans retinyl esters during normal retinal development and as control data in parallel investigations on mice with inherited retinal degenerations (C57BL/6J rdle/rdle and C57BL/6 pcd/pcd). Such analyses will provide additional information towards understanding the underlying mechanisms that lead to degeneration of the retina in inherited retinal disorders affecting lower animals as well as man.